On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Mentoring today - the students views: An investigative study of pre-registration nursing students' experiences of mentoring in one theory/practice module of the Common Foundation Programme on a Project 2000 course

The study reported in this paper investigated the mentoring experiences and perceptions of pre-registration nursing students in one organization, on a theory/practice nursing module. It considered the extent to which students' understanding and expectations matched their actual experiences. Interviews were conducted with 35 students on a Common Foundation Programme, and 15 allocated mentors, using a semi-structured interview guide. These were done within the clinical setting of the wards on which the students were placed as part of their requirements for completion of the module. A distortion of the actual meaning of mentoring appears to be present because of the lack of clarity provided, both internally by organizations and by the English National Board (ENB) who have provided loose guidelines. The implications of this distortion are discussed. The application of a mentoring role in practice needs to be re-examined, with the provision of a clear structured guide internally and externally, with regard to the needs of students and staff who are expected to act as mentors. The study was small scale and cannot be generalized. Mentoring, however, is now widely used within pre-registration nursing education, even though it is generally considered that its use may not be appropriate. Follow-up studies need to be undertaken on an ongoing basis, to examine what actually happens in practice, and to consider ways of ensuring that the benefits for staff and students are enhanced